This invention relates to automotive air conditioning and in general, and specifically to novel design for automotive heat exchanger mounting and support brackets.
Automotive condensers comprise a basic central core comprised of regularly spaced tubes and intermediate corrugated air fins, framed on four sides by a pair of parallel header tanks and a pair of parallel core reinforcements. Typically, the condenser header tanks are vertically oriented, and the tubes horizontally oriented. Some means is necessary to mount to condenser physically to the vehicle, generally in front of the engine cooling radiator. The condenser may be mounted directly to the vehicle frame, or indirectly mounted to the vehicle by mounting to the radiator. Whether it""s directly or indirectly mounted to the vehicle, the condenser generally requires several brackets, securely fixed to its core structure, which can in turn receive threaded bolts or other fasteners to allow the condenser to be fixed in place. Another structural concern with condensers is the refrigerant inlet and outlet pipes to the headers, which are connected to the refrigerant lines of the vehicle after the condenser is installed. The act of connecting the lines subjects the pipes to a predetermined level or torque relative to the condenser. At least one of these pipes is typically elongated, in order to accommodate the location of the refrigerant lines, and consequently needs extra structural support to resist the installation torque without being damaged or deformed.
The alternatives for providing mounting brackets on the condenser include extruding the header tank itself with integral rails, or attaching separate brackets. Integral rails are heavy, being the full length of the extruded tank, an example of which may be seen in U.S. Pat. No. 5,671,803. Much of the weight of an extruded header tank rail can be machined away in a post extrusion manufacturing step, leaving only a discrete flange, but the extra step adds expense. Most separate mounting brackets are metal pieces that are somehow fixed to the header tank before the brazing operation and then brazed on solidly later. Numerous examples may be seen in the prior art, as in U.S. Pat. No. 5,205,349. The addition of discrete, localized metal masses to an otherwise regular metal part is undesirable in that it can introduce irregularities in the braze temperature profile, as well as interfere with the smooth stacking and running of parts on the conveyor belt. Separate mounting brackets may also be attached after the brazing operation, as shown in U.S. Pat. No. 5,535,819, where metal brackets are bolted to the condenser reinforcement after the braze operation. One or more fasteners are needed for each of four brackets, which involves considerably more labor than simply snapping a bracket to a header tank prior to the braze operation. One recent U.S. Pat. No. 6,202,737, shows a condenser attached to a radiator tank with a bracket that is described as being xe2x80x9cnestedxe2x80x9d on top of the condenser tank before being snapped to the radiator tank. It is unclear what xe2x80x9cnestingxe2x80x9d means, and unclear what material is used in the bracket. The bracket shown provides no support to the condenser inlet and outlet pipes.
As noted above, another concern with condensers is support of the inlet and outlet pipes. Many patents showing separate condenser mounting brackets disclose using some portion of the mounting bracket to also provide locational support to the inlet and outlet pipes. Examples are U.S. Pat. No. 5,509,473 and the already noted U.S. Pat. No. 5,205,349. Others show separate brackets independent of the condenser mounting brackets and added just to help support the inlet and outlet pipes, such as U.S. Pat. No. 5,429,182. In addition to having all the drawbacks noted above relative to how the brackets are attached, such pipe support brackets, while they may help the hold the pipe in the right location for later refrigerant line attachment, generally do not provide significant resistance to the installation torque as defined above. Consequently, it would still be necessary to provide a back up wrench to the fitting at the end of the inlet or outlet pipe as the refrigerant line was attached, rather than a simpler and more desirable xe2x80x9cone handedxe2x80x9d operation. Without the back up wrench, the condenser pipe could be twisted and damaged by the torque involved. A known structure for providing xe2x80x9cone handedxe2x80x9d attachment of the refrigerant line to the condenser is a heavy joint block brazed directly and solidly to the condenser tank, so that a mating block on the refrigerant line can be bolted to the header tank block. An example may be seen in Japanese Published Patent Abstract 05203387. While allowing one handed attachment, the header block shown represents a large and undesirable thermal mass in the braze operation.
The subject invention provides a condenser mounting and inlet and outlet pipe support structure that resolves all the drawbacks and shortcomings noted above. The brackets are simple and light molded plastic pieces that are attached to the corners of condenser core entirely post braze, in a simple press fit operation that needs no separate fasteners. At least some of the brackets also have inlet and outlet condenser pipe supports that support the pipes solidly enough t o allow for one handed installation of the refrigerant lines thereto.
In the embodiment disclosed, the condenser has a typical core bounded on four sides by a xe2x80x9cframexe2x80x9d consisting of two extruded header tanks and a pair of stamped, beam shaped core reinforcements. Both the header tanks and the core reinforcements are simple, regular parts with no separate brackets, rails or flanges to create discontinuities during the braze process. The four brackets are hollow, light weight molded plastic pieces, each of which is mounted to a respective corner of the condenser xe2x80x9cframe.xe2x80x9d Each bracket has a cap that fits closely over the end of header tank and an integral channel on the side that snap fits over the core reinforcement, with no additional fasteners needed. Each bracket also has a bolt slot or other mounting feature to allow it to be mounted to the vehicle body or radiator. Once installed to the condenser core, the brackets gain solid twisting resistance from both sides of the condenser corner, as well as solid removal resistance from the close, snap fit. Two of the brackets are also molded with reinforced support flanges, to which the end of the condenser inlet or outlet pipe is solidly bolted or otherwise attached. This allows the refrigerant lines to be attached to the inlet and outlet pipes with no need for additional torque resistance.